CN85107495A - Cast iron particularly contains the production method of cast iron of the China ink of wriggling - Google Patents
Cast iron particularly contains the production method of cast iron of the China ink of wriggling Download PDFInfo
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- CN85107495A CN85107495A CN85107495.2A CN85107495A CN85107495A CN 85107495 A CN85107495 A CN 85107495A CN 85107495 A CN85107495 A CN 85107495A CN 85107495 A CN85107495 A CN 85107495A
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- Investigating Or Analyzing Materials Using Thermal Means (AREA)
- Sampling And Sample Adjustment (AREA)
Abstract
The present invention relates to the method that a kind of usefulness contains the Cast Iron Production foundry goods that improves additive in a organized way.And preferable additive can make carbon deposition become to wriggle the form of China ink.The invention still further relates to various concrete samplings and test chamber.
Description
The present invention relates to a kind of production and contain the method that tissue improves additive cast iron, and preferable additive can make carbon deposition become the to wriggle form of China ink.
In ISO/R945-1969, the China ink of wriggling is named to be then to be referred to as " the 4th type " A by ASTM specification sheets A247 by " elicit illness state " graphite.
Cast iron is the most basic material in the industrial casting technique, and can make carbon deposition become the form of cementite Fe C after solidifying, and forms white cast iron or grey cast iron.White cast iron enbrittles, and so its ultimate compression strength is high and extremely wear-resisting.Grey cast iron is easy to processing, thereby application is very widely arranged in the mechanical technology field.Graphite generally precipitates into sheet in the grey cast iron.This just makes this cast iron have limited breaking strain (0.5%).Grey cast iron has good heat-conductive characteristic, but in the back of heating nonvolatil volume change takes place, and this has just limited its application in some aspects.Therefore, there is the people aspect change aquadag form, to carry out many research work at some additive of interpolation.In this respect, generally can use magnesium or magnesium and rare earth metal, for example cerium combines use, these improve the growth that additives have stoped flake graphite, cause graphite to become ellipse garden ball or spherical.Such material is known as spheroidal graphite cast iron.Spheroidal graphite cast iron has been used as structured material increasingly extensively in construction applications.In the field further develop the formation that relates to other graphite form.In the graphite of these other forms, great majority all can form, but industrial application is also restricted.Yet, having now found that so-called compacted graphite iron castings or the so-called iron of wriggling have some characteristics, these characteristics make this cast iron have special significance.And these character make this cast iron more superior than grey cast iron and spheroidal graphite cast iron in many different Application Areass.But, the existence that additive departs from aequum and impurity a little all is that those make this cast iron can not use cheap raw-material factor, thereby the production of this cast iron is confined to casting producer of several family always, these producers are owing to test and test in a large number and owing to use strict regulation by rule of thumb and expensive often raw material and additive, thereby set up a special knowledge.
Therefore, objectively require to have a kind of method, by this method people can reappear with the melt solidifying iron that becomes to wriggle, thereby control producing of any cast iron materials melt.
When the casting metal, the factor of process also is the deciding factor that influences the finished product performance after the bath component crystallization though physical condition and other influences, and vital still is bath component.
The chemical constitution of melt, for example alloy element, impurity, gas content or the like analysis of modernization instrument that can carry out necessary calibration is monitored rapidly and is checked.
But, on the other hand, so far also do not work out any perfect method, the melt that can predict and control certain material with this method rapidly, reliably solidifies the crystal structure properties that the back is obtained under curing condition commonly used, although in relevant document, find to have put down in writing many test and researchs of being carried out for this purpose, and also have the patent application of many relevant this methods.
Cast material can be divided into two big classes by the character of its process of setting, and the first kind wherein is the material of single-phase solidifying (first process of setting).This class material comprises steel, aluminium alloy and the copper alloy of most of kinds.The another kind of material that comprises two-phase or multiphasesolidification (secondary process of setting).The material that belongs to this class has the cast iron and the sial type aluminium alloy (Al, 8-12% Si) of various kinds for instance.
Therefore, the objective of the invention is to propose a kind of method of major control molten state cast iron secondary process of setting, so as with comprise common facile raw material iron and steel scrap interior before this always can not with raw material smelt compacted graphite iron castings or vermicular cast iron.
For this purpose, adopted a kind of thermoanalysis technology, promptly along with the temperature of the sample different sites that takes out in the melt of studying is certainly measured and write down in the continuity of time.
This temperature one time record technology itself is not new technology, and nothing but a kind of classical way of measuring invert point and temperature of fusion.Crystallization transforms generally to be carried out at a certain temperature or in certain temperature range.
In this technology, with a kind of temperature sensing device, for example thermometer, thermopair, thermistor or other allied equipment are placed in sample or the test chamber, perhaps make it to contact with sample or test chamber, and sample or container are pressed preset program heating or cooling.The record invert point also can select to write down the derivative of freezing curve arbitrarily, perhaps record survey poor with between the respective counts numerical value of known reference material.
This method has been used for carrying out the rapid chemical analysis in the metallurgy field, for example be used for precipitating the so-called carbon equivalent (CE) in the cast iron
(CE=total carbon per-cent+(%Si+%P)/3), during measurement the sample of melt to be poured in the casting sand sample cup, a thermopair has been settled in the centre of sample cup.When iron crystal (austenite) forms in melting material, can see that freezing curve has a straight portion, it is consistent with the correction of used sampling system that this straight portion has disclosed carbon equivalent.Therefore, this common instrument is suitable for carrying out the real-time analysis of iron component on principle, but it does not a bit disclose the presumable crystallization mode of formed austenite.Except other company, this instrument is by U.S. Leeds ﹠amp; Northrup company sells, and its trade name is " TECTIP ".
Similarly instrument also has been used for measuring the eutectic growth temperature in iron-carbon-silicon system, and is used for measuring eutectic reaction degree of supercooling before.But, when but showing melt solidifying unsatisfactorily and the crystalline structure that reckons with in the above-mentioned eutectic reaction process with the resulting take off data of this instrument.Melting charge is poured in the instrument of cold mould at those, be close to cold die wall moment formation skim solid phase, wherein produce the iron have the graphite phase and have carbide iron mutually, and under the suitable growth temperature of each phase, above-mentioned each do not reach mutually form new nuclear or again the necessary overfreezing limit temperature of nucleation just can grow very simply.
In spheroidal graphite cast iron method effectiveness of application,, delivered one piece of criticism property comment on the 307th page the-the 311st page for this method in the american foundrymen's association proceedings of publishing recently 82: 131.This comment points out that the tolerance range reliability of this method when mensuration is organized remains on 80% level of confidence, and this level of confidence is compared far away and can not be satisfied the demand with the coml working system.
Need measuring method to wriggle China ink more accurately when forming when attempting indication, can expect to obtain, measuring result is poorer.
But some is overcome the basic weak point of these in the modern thermoanalysis technology by the technology of being set forth among the Swedish patent specification No350606.
With this technology can measure that real supercooled state and crystallization form and process of growth in growth temperature.During measurement sampling container immersed in the melt or, make container and content thereof under the both of these case before process of cooling begins, be issued to thermal equilibrium in the temperature that is higher than Tc with other method heating container.Measure supercooling temperature before in nucleation, recalescence (by the hot reheat that crystallization discharged) reinforcement and time length (representing by the time length of maximum value and positive derivative the most simply), can improve announcement like this various crystal growth phenomenons in the process of setting.But, when measuring the eutectic reaction of cast iron, also have a problem; Recalescence effect and growth temperature are not only decided with growth forms, but also decide with formed graphite crystallization concentration (the graphite crystallization number of=per unit volume), and this method can not be distinguished this two kinds of factors, and this difference forms and makes the correct direction of process guide for the indication tissue is necessary.
Can measure other performance of solidifying material, for example dimensional change (using dilatometry) or be lower than thermal conductivity (Swedish patent application No7805633) in the about 100 ℃ of complete cakey samples of temperature of solidification.But, measure tissue with these methods and form, all can not have sufficiently high tolerance range, no matter with regard to regard to the morphology or with regard to graphite phase disperse degree.
As an achievement of the present invention, people can use once on hot analysis foundation new developing technology and determine that reliably the tissue of melt solidifying in the actual process of setting forms situation from now on.According to this new technology, from the melt that will study, take out a duplicate samples, it is transferred in a sampling and the test chamber, heat this container and make it to reach thermal equilibrium, write down on the position of sample centre and next-door neighbour's sampling container wall temperature simultaneously over time at the fusing sample that is higher than under the temperature of Tc with wherein being held.So just obtain two freezing curves disconnected from each other, the situation of process of setting when they can provide relevant the casting.(the following sampling container that only abbreviates as in fact also can be understood as test chamber).
What the present invention relates to is that a kind of usefulness contains the method that tissue improves the molten cast iron production foundry goods of additive, it is characterized in that, prepares a kind of primary molten cast iron; Take out a melt sample with sampling container; Make that duplicate samples of being taken out be in abundant thermally equilibrated state under its temperature of melt crystallization temperature and begin to solidify being higher than from take a sample container and institute's sample thief, that duplicate samples of being got is solidified in 0.5～10 minute time fully, measure and write down temperature-time series with two temperature sensing devices simultaneously, one of temperature sensing device be placed on institute's sample thief centre portions another then place the melt of next-door neighbour's sampling container wall.In near the melt wall of container in first crystallisation process near measured temperature, near the recalescence (rckv) the wall of container, the said vesse wall and the positive temperature difference (△ Tt) and note ((dT)/(dt)) (T at sample fort heart position
cMax) thermograde at rear portion, eutectic growth forward position (has for some time constant at least in the eutectic growth process in institute sample thief centre in the sample, i.e. ((dT)/(dt)) c=0) selectively is expressed as maximum subzero temperature difference (△ Tmax) is determined the graphite phase with respect to the known reference value of same sampling system gained disperse degree arbitrarily, then the graphite nucleator is introduced wherein when the nucleus in the melt is not enough with this, otherwise when finding that crystallization nucleating agent then makes its minimizing when excessive.The form of aquadag is that known reference value with respect to same sampling system is with melt centre temperature (T
c), the recalescence (rckc) and the maximum growth temperature (T in centre
cMax) measure, calibrate the amount that existing tissue improves additive then, so that graphite precipitates into vermiform in the process of setting of molten cast iron after casting.
The contrast accompanying drawing describes the present invention in detail below, and wherein Fig. 1 solidifies figure with what the observed value that smelting obtains during vermicular cast iron was done,
The suitable various concrete sampling container example that uses when Fig. 2, Fig. 3 and Fig. 4 have illustrated by this method of the invention process.
The following general designation of Figure 1A and 1B(Fig. 1) shown in is temperature (T) time (t) curve, and curve I is wherein represented to be close to the process of setting that carry out at sampling container wall position, and the curve II is represented the process of setting that carry out in the sample centre in the container.
From these two curves, label 1 expression produces heat when forming owing to the austenite first phase and makes that temperature descends in the time per unit.Label 2 on the curve II is represented that austenite crystallization (dendritic shape (dividing dendritic)) formed in entire sample.With after this, carbon in the fused sample (and other alloy element) is enriched between the austenite crystallization, so that forms eutectic mixture gradually when sample temperature continues to descend.
The terminal point that label 3 expression temperature on the curve I descend.Along with abundant cold excessively, near wall of container, formed graphite crystallization, and the iron phase in these crystallizations and the eutectic mixture is grown simultaneously.After this step of process of setting, fusing sample is reheated owing to recalescence, the equilibrium temperature of trend eutectic mixture.This marks with dotted line TEu in Fig. 1.But, do not reach the constant growth conditions relevant fully at the commitment of this eutectic reaction, and therefore the speed of recalescence substantially represent the active graphite check figure in the per unit volume with growth inhibition mechanism.Equally, the maximum undercooling point T*c of 4 expressions of the label on the curve II; Label 6 is represented the recalescence curve; Existing growth temperature when on behalf of the sampling container centre, label 7 then place stable state.The situation of growth mechanism when these values provide relevant eutectic solidification state.
Near the wall of container temperature can be described as " instantaneous picture " that representative limits crystallisation process in the melts volume (thin-walled), and the temperature at container center position has then been represented " complete " image of entire sample inside.In the sample between two temperature measurement locations the temperature through making progress may be a kind of temperature wave, it is propagated forward and has reflected along the growth order on the eutectic solidification face of inward oriented development.In fact, this meaning has shown process of setting corresponding to thin-section casting than the thermopair of outside, and the thermopair in centre then provides the order that solidifies of relevant foundry goods than thickness portion.Instead when the information summary of this two aspect being got up just might draw relevant melts forms required organizational capacity in the different thickness foundry goods in casting and process of setting conclusion.
The type of process of setting is main relevant with the hypereutectoid cast iron composition.But this method also can be applied to the cast iron of eutectic and hypereutectic composition.First crystal growth does not take place when eutectic composition solidifies, and first aquadag only just takes place when hypereutectic composition is solidified.
Find by test,, then form flake graphite if inabundant cold excessively, faint recalescence and high growth temperature are preponderated in the process of setting.
On the other hand, if high supercooling temperature, little recalescence and low growth temperature are preponderated, show that then graphite will solidify with spherical, and will obtain spheroidal graphite cast iron.
When the China ink of wriggling dissociated in process of setting, then generation exceeded cold, strong recalescence and high growth temperature.
Show fully and can in these big classes, segment, thereby can indicate that the China ink of wriggling forms with the determinacy of height that it conversely again can be with technology controlling and process in the extreme value scope of refinement more by the deviation shown in the curve.
Suppose that external conditions all keeps identical in all cases, just can will near placing the sampling container wall, compare, and can two values that different tests write down that melt carries out be compared with two values that temperature sensing device write down of putting the fusing sample centre.Certainly, technical difference is different with the sampling container geometrical shape, and the difference of institute's package material is necessary to make it to be small enough to the testing data that the enough different sample acquisitions of energy have repeatability and are more or less the same in the container.
The sampling container that some are suitable to be used for carrying out setting test will be illustrated according to Fig. 2 to Fig. 4 hereinafter.Certainly, the research method that is adopted must be identical for each sample or for testing at every turn, so that reach temperature equilibrium between melt and the sampling container.Regulate sampling container temperature on every side, make sampling container can come dissipated heat in the mode that for some time of 0.5～10 minute solidifies with melt.Owing to the steady system formation cementite that is situated between is comparatively fast pressed in cooling, thereby controlled lower value.From the angle of producing, speed of cooling is slower than 10 minutes and does not conform to practicality, moreover the tolerance range of measured data is also owing to inside and outside other reaction that is taken place of container and owing to convection current reduces.Ideal cooling time is 2-4 minute.Though the size of sampling container or test chamber is owing to its diameter of the reason in the practicality should less than about 2 centimetres or greater than about 10 centimetres, lotus not be asked so.Suitable diameter is 3-6 centimetre, and self-evidently is, container suitably contained some centimetres height and sample contain height must not be greater than its diameter.Can guarantee that preferably heat basically through upwards, comes out from sampling container.Upper/lower terminal with sample insulated just can reach this purpose.
Though the sampling technique that is adopted is not quite similar between series and series, self-explantoryly be, then must be identical in the specific sample series that will compare.When melt material is taken a sample, sampling container can, for instance, immerse in the melt and remain on wherein, be heated to the temperature of melt up to it.What can support selection is, can earlier sampling container be preheating to the temperature of melt, contain melt material then, and another kind of suitable method is, before the record freezing curve, test chamber is put into independent heating chamber or stove together with the molten state sample that is wherein held, be heated to thermal equilibrium then.Revision test can be carried out like this, promptly immerse sampling container in the melt and write down the freezing curve of institute's sample thief, and then container immersed in the melt together with the sample that has solidified again, make the sample refuse of having solidified and container is packed into again new sample.
The solidification layer thermal conductivity of the release of latent heat and eutectic growth forward position (it is relevant with corresponding growth mechanism) and back, eutectic growth forward position not only depends on the graphite crystallization number in the eutectic structure to heavens, but also depends on above-mentioned crystalline shape to heavens.The appropriate method of measuring this compound action draws by being determined at resulting slope () in the process of setting, this slope is with placing near the container temperature sensing device when that time of the temperature sensing device record plateau temperature (the temperature T max when being equivalent to the eutectic stable state) that places the container center position, and promptly () c is measured in null that time.This compound action also can be measured with the method for measuring in the process of setting maximum temperature difference (△ Tmax) between two curves.Have now found that in both cases, numerical value is not different yet simultaneously for graphite shape in the cast iron.Grey cast iron contains flake graphite, but the temperature difference between two freezing curves is little.The △ Tmax of spheroidal graphite cast iron is big, and the numerical value of cast iron solidified one-tenth when wriggling iron falls between, in having provided the very big possibility of solidifying character with differential method evaluation different melt.
(when austenite became ferrite and cementite (point 8), its speed and last tissue can be with the methods of two measurement point deviations of comparison and are particularly moved with the method for differentiation function value with the comparison time and further investigate in solid phase at eutectoid transformation.
(use graphics or use other recording unit with come comparison with the resulting response curve shape of the sample of known crystalline characteristics with two freezing curves of unknown sample record and with these curve shapes except above-mentioned, data processor for example) beyond the possibility, smelting contain solidifiable wriggle the China ink cast iron the time, following performance also is a feature.
The reliable method of black growth forms of determining to wriggle is cold excessively (T*c), recalescence order (rekc) and the highest eutectic growth temperature (Tmax) of utilizing the centre.
Actual disperse degree (this paper is referred to as the graphite crystallization number of per unit volume) can be measured by the temperature curve of first eutectic life nuclear process with the recalescence order (rekv) at nearly wall place, △ Tmax or the () v when the Tmax.First gives birth to nuclear process is regarded as degree of supercooling T*v usually, but under graphite nucleogenesis very intensive situation, the retardation of cooling curve shows has a small amount of flake graphite to form.
Repeatability can accurately be measured and have to all values that this paper lifted, and repeatability can be evaluated the intrinsic crystal property of melt.
Because above-mentioned these variablees are relevant each other, so might not always need to use all these variablees, shown in above-mentioned and the system of then calibrating, only use a few above-mentioned variable just enough, and need only with the some crystallization properties that can measure single melt in the above-mentioned variable in some cases.In some such systems, can obtain the major portion in the relevant situation with the temperature sensing device of single eccentric arrangement.
Those of skill in the art in the casting technology field can determine should select which above-mentioned data of advising for wanting actual production to go out stable vermicular cast iron, and how write down and evaluate take off data fully.Self-evident, the simplest method is that recording curve and the typical curve through calibrating that will be basis compare with the measured value, only manages these numerical value and also can come comparison by datamation with digital form.
In order to illustrate these different possibilities, Fig. 1 with the diagram method representation mark and draw the curve of time T by the difference of two curves, the curve I subtracts the curve II and equals △ T, positive △ T value zone is represented with the zone of being decorated with the shadow line among the figure, and draw () of two curves at last, above-mentioned each numerical value among the figure is expressed with the derivative form, and rekv and rekc are to represent on the occasion of the shadow district.
So just can read those in order to obtain the observed value that required result should adopt, select to adopt further sampling and test method to show the result who reaches required then from diagrammatic curve.The knowledge of melt crystallization characteristic can make must adding of related substance or remove and carried out, and also can in this field those of skill in the art's special knowledge scope, fully automatically measure crystallization property with the data program technology, automatically correct the composition of melt then, so that obtain vermicular cast iron.The speed of solidifying will depend on thermal conductance heating rate, the wall thickness of wall of container, the volume-surface ratio and the envrionment temperature of sample.Although these parameters can change, be understandable that these parameters that adopted must make sampling or test method implement in the mode of practicality, and can be used for the foundry goods of different size.
Sampling container to be cooling off in the simplest method atmosphere at ambient temperature, although solidify the process that also can put off solidification easily in temperature is in heating chamber between cast iron fusing point and the envrionment temperature.Setting time also can adopt the way of adiabatic sampling container to prolong, and perhaps places jacket to prolong setting time in container in solidifying treating processes.Also can come the accelerated solidification process in case of necessity with freezing air, small-sized spraying or certain similar method.Briefly describe the form that sampling unit is got, this is impossible, although this is to lean on this professional domain those of skill in the art's special knowledge to come the design sample test method in the mode that realizes the condition of being lifted in the following claim.
Before beginning to carry out measuring process, whole device, sampling container, heating chamber and the melting material that is placed in one all must really be in thermal equilibrium under the temperature that is higher than the sample fusing point.For cast iron, this is equivalent to about 1200-1400 ℃ temperature.
For instance, sampling container and temperature sensing device are combined in some way, they can be immersed in the melt that has been heated to about 1200-1400 ℃ temperature, and before whole device is heated to this temperature, be retained in wherein always, so just can reach equilibrium state.From melt, take out and make it cooling then.Temperature sensing device is connected with the recording unit of certain form again, and recording unit stores take off data with analog form or mathematical form.
Therefore can know that sampling container or test chamber can different forms constitute, Fig. 2 to Fig. 4 has illustrated three kinds of concrete sampling container or test chambers that are fit to use.
Shown in Figure 2 is a kind of concrete sampling container or test chamber of suitable use, and it can immerse in the hot melts, and this container has a housing 1 that is caused by heat-stable material, and suitable heat-stable material is a ceramics material.Housing 1 is attached on the root tubular component 2, can fixed container and container immersed in the melt with this element.An opening 3 is arranged on the housing 1, can flow among the housing by this opening molten state material.Settle two thermopairs 4 and 5, one positions that place next-door neighbour's housing wall 4 in housing, another places the centre of housing.Thermopair is linked on the registering instrument (not shown) by lead 6.
Shown in Figure 3 is another kind of concrete sampling container or test chamber, and it can contain the melt material of heat, so that analyze.This a kind of concrete container has a shell 7, and induction device 8 and 9 is inserted in the bottom by housing, shown in one of temperature sensing device (8) be placed near on the position of housing wall, another temperature sensing device (9) is placed in the centre of housing.Container is with resistive heater 10 outward, is used for preheating container.Temperature sensing device 8 is connected with the registering instrument (not shown) with 9 mat leads 11.
Shown in Figure 4 is another concrete sampling container or test chamber, and its housing 12 is with radio-frequency heater 13, the sample that is used for the reheat container and is wherein contained.The molten state material can be transferred in the container with spoon.The housing 12 of this concrete container has a lid 14, and lid has guide bracket 15, is convenient to lid is enclosed within on the housing 12, covers the temperature sensing device 16 and 17 that downward stretching, extension is housed, and they are connected with the registering instrument (not shown) by lead 18.After container and the sample that held thereof were heated to essential temperature, the lid that will have temperature sensing device covered on housing 12.
When enforcement is of the present invention, smelt a kind of molten cast iron of routine earlier, its chemical constitution is adjusted to required value according to chemical analysis.Then, get a melt sample and carry out heat analysis and record freezing curve by the present invention.The intrinsic nucleation ability of evaluation melt is also added requisite oxide compound-sulfide formation agent, so that obtain needed first nucleation ability.The oxide compound that is suitable for forms agent and sulfide formation agent example has calcium, aluminium and magnesium.Another prerequisite of graphite nucleation is that it is high fully that carbon equivalent ce is wanted.Subsequently, add the material that certain can improve carbon equivalent ce in the part, for example ferrosilicon, quartz or silicon carbide are examined to promote to give birth to.Although adding this way of giving birth to the nuclear agent is well-known in this professional domain, fail before this with known measuring method with required addition before the definite casting of enough pinpoint accuracy always.
The living nuclear capability of relevant Tv* and rekv and the particularly important situation aspect the △ T function after calibrating system, have been obtained.The deficiency of living nuclear agent can increase cold, and this increasing is increased in the generation of the edge section of sampling container to the steady system conversion that is situated between under some situation.Recalescence takes place when white cast iron solidifies especially rapidly.In order to form spheroidal graphite cast iron, the formation of nuclear must be than forming required big hundreds of times of flake graphite.In order to obtain vermicular cast iron, give birth to nuclear capability and must be advisable with 1/10th the order of magnitude than forming required little of spheroidal graphite cast iron.If measured living nuclear capability is low especially, then can add and give birth to nuclear promotor, if instead need lower living nuclear capability,,, the nucleation ability reduces because prolonging with retention time as long as then allow melt leave standstill certain hour.
Tissue improves the amount of active substance and is regulated according to cold excessively (T*c) in molten state material centre, the recalescence (rekc) and the maximum growth temperature (Tmax) in material centre.When sample solidified, existing tissue improved the amount of active substance and can grow up by crystallization control.If formation graphite granule, then on three directions, all be restricted at aquadag crystalline growth to a certain degree the time, if obviously reduce with respect to obtaining the globular graphite aequum but tissue improves the amount of active substance, then crystalline growth only is restricted on both direction, crystalline growth in the molten metal might be carried out on third direction, and such crystalline growth just forms the China ink of wriggling.Analyze above-mentioned each value (T*c, rekc and Tmax) and will disclose the tissue improvement active substance whether melt has q.s.When finding that it contains quantity not sufficient, just add tissue and improve element.Magnesium and optional rare earth element, for example cerium combines together and can be used for this purpose.Too high tissue improves substances content and can adjust with oxidation style, and oxygenizement can realize that perhaps can add certain oxygenant by mat, for example magnetic iron ore is realized by mat logical oxygen in melt.Oxygenizement also can mat be exposed to the air some minutes with the metallic surface and realizes, also adds retarding agent in the melt in the past, and for example titanium reaches and reduces the purpose that tissue improves active substance content.
The problem that the present invention at first will solve is that castingprocesses has been controlled to the black sedimentary process of setting of wriggling.Though accurately measure the disperse degree and control sedimentary flake graphite type when so, this method is still to the smelting grey cast iron significant possibility is provided with this.This method also can accurately precipitate tissue and improve amount of substance and needed disperse degree when smelting spheroidal graphite cast iron, thereby can save expensive additive.
Gained coagulates in the curve irregularity that trend coagulation phase terminal point place occurs and can also show and might form carbide during the measure sample centre, the formation of carbide shows with the common living nuclear agent that exists of carbide stable element in shortage conversely again valuably, is come out by segregation in microstructure.
Same self-explantoryly be, in the casting technique field, always adopt certain through the effective calibration steps of evidence, it is decided with local condition, and melting tank and can optional melt processed device, the type and the structural configurations formula of the casting device of the attemperator and the foundry goods kind of producing etc. combine.Existing analytical procedure and measuring method have been brought into play maximum available degree in this technology, the present invention has then solved the difficult problem of the ubiquitous control of material of foundry industry aspect with this kind method.
Be apparent that, can derive a series of mutually different factors from freezing curve during casting technique in control, and the analysis that can choose wantonly of the entire curve shape of getting, and can compare with known whole process development.Modern data processing technique can the various virtual value of decimal numeration computing and is compared with corresponding reference data, makes melt processed technology on this basis with being controlled by optional fully automatic system.
Claims (5)
1, a kind of usefulness contains the method for the Cast Iron Production foundry goods that improves additive in a organized way, it is characterized in that, smelts the fused molten cast iron; A kind of sampling of mat and test chamber take out a melt sample; Make that duplicate samples of being got be higher than from container and sample that abundant thermally equilibrated state begins to solidify under the melt crystallization temperature, and sample is solidified fully in for some time of 0.5～10 minute, measure and write down one time of temperature sequence simultaneously with two temperature sensing devices, one of them temperature sensing device is positioned at the centre of sample, in the melting material of another next-door neighbour's wall of container; With respect to the known reference value of finished product cast with identical sampling test method gained, with near the first measured temperature (T*v) in the secondary nuclear process of the eutectic reaction of the said vesse wall, measuring, near the wall of container recalescence (rek), near the positive temperature difference (Δ Tt) at the wall of container and container center position, and near the sample centre eutectic growth homo(io)thermism derivative (Tmax) that promptly temperature is fallen=0 the time inner reservoir wall, optional maximum subzero temperature poor (Δ Tmax) is evaluated the disperse degree, thereby when the nuclei of crystallization in the melt are not enough, give birth to the nuclear agent to wherein introducing certain graphite, otherwise when the agent of the living nuclear of crystallization is excessive, then before casting, keep melt, to reduce the disperse degree; With respect to known reference value with identical sampling and test method gained, cold excessively (T*c), the recalescence (rek) in centre and the form that maximum growth temperature (Tmax) is evaluated aquadag with the generation of melting material centre, and the amount of correcting texturizers in view of the above, graphite is precipitated by predetermined shape when casting after coagulation at molten state cast iron.
2, the production method of the described iron casting of claim 1, it is characterized in that, make the take off data that write down consistent by identical sampling and the resulting corresponding data of experimental technique with known cast iron with the China ink tissue of wriggling, control giving birth in the melt with this method and examine agent content and texturizers content, thereby make graphite when fused cast iron solidifies, precipitate into vermiform after cast.
3, the described method of claim 1 is characterized in that, sampling container is immersed in the melt, has contained the temperature that the molten state material takes out this container later on and is heated melt at this container, and sample is obtained from melt by these steps.
4, the described method of claim 1 is characterized in that, from melt, take out sample and with this sample transfer in a kind of sampling and test chamber, make sample this container is preheating to the temperature that probably equals melting material before solidifying immediately.
5, the described method of claim 1, it is characterized in that, from melt, take out sample and with this sample transfer in a kind of sampling and test chamber, make sample this container is heated to temperature equilibrium corresponding to melt temperature together with the molten state material that is wherein contained before solidifying then.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 85107495 CN1015114B (en) | 1985-10-09 | 1985-10-09 | Method for controlling and redressing graphite precipitation form during producing castings with cast-iron contg. additives for improved texture |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 85107495 CN1015114B (en) | 1985-10-09 | 1985-10-09 | Method for controlling and redressing graphite precipitation form during producing castings with cast-iron contg. additives for improved texture |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN85107495A true CN85107495A (en) | 1987-08-19 |
| CN1015114B CN1015114B (en) | 1991-12-18 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 85107495 Expired CN1015114B (en) | 1985-10-09 | 1985-10-09 | Method for controlling and redressing graphite precipitation form during producing castings with cast-iron contg. additives for improved texture |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110835667A (en) * | 2019-11-29 | 2020-02-25 | 共享装备股份有限公司 | Method for accurately controlling residual Mg content in nodular cast iron and vermicular cast iron |
-
1985
- 1985-10-09 CN CN 85107495 patent/CN1015114B/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110835667A (en) * | 2019-11-29 | 2020-02-25 | 共享装备股份有限公司 | Method for accurately controlling residual Mg content in nodular cast iron and vermicular cast iron |
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| Publication number | Publication date |
|---|---|
| CN1015114B (en) | 1991-12-18 |
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